Email header analyzer

Email header analyzer reads a pasted header in the browser and lists each hop and the authentication results. Nothing you paste is uploaded.

Hop 1 is the first Received line, the hop closest to the receiver. Later hops are closer to the sender. SPF, DKIM and DMARC are read from the Authentication-Results header in the paste. Alignment says whether the SPF mail-from domain and the DKIM d= domain match the From domain, or sit under it. A missing header is reported as missing. There is no score, and this page does not check whether a server is listed anywhere.

The SPF, DKIM and DMARC checker reads what a domain publishes. The email deliverability test gives you an address to send to. The bounce decoder reads a diagnostic.